Thermal inkjet printheads employ drop ejectors which include firing resistors to vaporize fluid in firing chambers, resulting in droplet ejection through nozzles respectively associated with the firing chambers. There has been a trend toward increasing the number of firing chambers and associated resistors on the printhead, leading to increased complexity in driving the firing resistors. In the past, multiple drivers have typically been used to apply the firing signals to different groups of firing resistors. Firing only one resistor at a time by a given driver reduces or prevents energy variation error terms that may occur due to parasitic effects, but at the expense of increased interconnection complexity and performance. For these and other reasons, there is a need for the present invention.